Europe's largest free standing terrace, where 25,000 of Borussia Dortmund fans congregate every other week for home games, has become one of the most intimidating sights for opposition teams -- and a source of strength for the home team.

Borussia Dortmund is the best attended club in Europe with more than 80,000 at home games, attracting bigger crowds than other footballing giants such as Bayern Munich, Barcelona, Real Madrid and Manchester United.

A stuttering season in the Bundesliga, with Dortmund currently in fourth place after Tuesday's draw with Augsburg, has been interspersed with a more successful Champions League campaign.

After topping Group F ahead of Real Madrid and scoring a record-breaking 21 goals in the process, Dortmund will now welcome Portuguese side Benfica to Signal Iduna Park in the last 16.